In valve assemblies, fluid flow is controlled by actuating a plug head assembly relative to a valve seat. In extreme operating environments, such as at elevated temperatures, pressures and/or corrosive or abrasive fluids, the components of a plug head assembly may weaken or become more loosely coupled than intended. For example, where a ceramic plug head is retained by a conventional retainer apparatus, the retainer apparatus may expand at a higher rate than the ceramic plug head, thus making the fit between the retainer apparatus and the ceramic plug head loose. In addition, thermal events and crushing lodged solids may cause fractures in a ceramic plug head, which may then separate from the plug head assembly or compromise the integrity of the plug head ceramic.
Ceramic plug heads, such as plug heads comprised of sintered silicon carbide (SSiC), are often used in extreme operating environments, such as high-temperature applications (e.g., from about 20° C. to about 260° C.), and/or high-pressure applications (e.g., from about 5 bar to about 47 bar), and/or applications involving highly erosive and/or corrosive fluids and/or slurries. Slurries contain both solids and fluids, which may flow at high speeds. Thus, solid particles traveling at high speeds also comprise an extreme operating environment. While ceramics like SSiC are suitable for use in extreme operating environments, such ceramics are typically brittle and susceptible to fracture/damage from environmental conditions (e.g., thermal shock) and events (erosion/corrosion/collision/crushing).
Thus, it is desirable to overcome at least a portion of these and other related limitations associated with plug head assemblies.